Now that Labour’s lead over the Tories has narrowed, and its decade-long dominance of the opinion polls is at an end, there has been much speculation about Michael Howard’s chances of becoming prime minister. In theory, of course, it is possible. Labour has never managed a full two-terms in office with a majority; we have never managed to win three elections in a row, and the Tories have done it twice in the past century. But even in their most fanciful moments, the Tories must know that for Howard to walk into Downing Street next year it would take an electoral earthquake, that would make Attlee in ’45, Thatcher in ’79 and Blair in ’97 look like tiny tremors. With Labour five points ahead of the Tories in February 2004, after Labour’s toughest period of office ever, Howard’s chances of winning the 2005 general election do not look good.

The scenario for which the Tory strategists are planning, is that Howard wounds Labour significantly, vaporises our majority, and leaves us in office, but impotent. This is what happened to Attlee’s Labour government in 1950, before losing in 1951 and staying in the wilderness for thirteen more years. It is what happened to John Major in 1992, before limping through five torturous years and finally being swept away in Labour’s landslide. A Labour government with a majority under 30 would place Blair in a difficult position: blamed for the loss of so many seats, denounced by scores of sour ex-Labour MPs, unsure of commanding a majority in the House of Commons for key legislation and prone to ambush by the resurgent Tories at any moment. That’s what the Tory high command, installed in their new Victoria Street offices (above Starbucks) are hoping for.

Tory hopes were given an incalculable boost by the recent vote on the university higher education bill, which saw Labour’s huge majority reduced by rebels to just five. Here, former ministers and whips were organising a sophisticated machine to persuade rebels to vote against the government, even though there was more at stake than university finances. In such a situation, a Labour government with a small majority would be unable to function. During the debates around the bill, a phrase crept into the discourse which we haven’t heard for a while: a party within a party. Veteran MP Jack Cunningham used it on the Today Programme: ‘I spent 18 years in opposition fighting on many fronts against, in particular, Militant Tendency, the hard left, to stop the development of a party within a party. That is another lesson the Parliamentary Labour Party must learn. A former chief whip, a former deputy chief whip openly, coherently working and planning to bring defeat to their own government? It gets perilously close to that, doesn’t it?’

So given the confluence of these two factors – a Tory party capable of winning seats from Labour and a determined group within the PLP willing to vote down government legislation – what could politics look like after the next general election?

Let’s look at two scenarios: a five percent swing from Labour to Conservative, and a ten per cent swing from Labour to Conservative. Leaving aside the usual caveats about non-uniform swings, and also the likelihood that even though the Tories may win seats from us, they may also lose them to the Liberal Democrats, what would happen? On a five percent swing, Labour loses roughly 50 seats to the Conservatives. Fifty fewer Labour MPs, fifty more Tories, plus a handful more Lib Dems, means a Labour majority of under a hundred. Manageable, but not great for Labour’s business managers.

But what does such a swing do to the loyalist/rebel balance of forces inside the PLP? Twenty-one of the 50-odd losers would be MPs who are currently on the ‘payroll vote’: ministers, whips, or PPSs. These are solid Blair loyalists. A further eight are loyalist backbenchers, who backed the government on the crucial higher education vote. So about 30 Blair loyalists would be polishing up their CVs on a five percent swing. There are only four members of the Socialist Campaign Group – the so-called ‘hard left’ (hardcore serial rebels) who would be joining them: Philip Sawford, John Cryer, Robert Marshall-Andrews and Ann Cryer. Inside the PLP, the swing is towards those willing to vote against the government and away from those who support it.

And what about a massive ten percent swing from Labour to Conservative (bear in mind Thatcher’s victory in 1979 was based on a 5.2 percent swing, and Labour’s in 1997 was based a 10.2 percent swing.)? The government would be in serious trouble. A ten percent swing wipes out about 130 Labour MPs, and with it Labour’s overall majority. With Labour on roughly 283 and the Tories on roughly 296, Labour would need the support of the Liberal Democrats to form a minority administration. This would be Blair’s killing fields. Just two further members of the Socialist Campaign Group would be out: Ian Gibson and Mike Wood. But 28 Labour ministers and PPSs would be history, plus a large swathe of habitually loyal backbenchers, most of whom owe their seats to the modernisation of the Labour party. This scenario would see a PLP which resembles much more closely, in terms of politics, the class of 1983.

So, a back of the envelope calculation shows that the bigger the swing to the Conservatives, the more New Labour loses disproportionately to Old Labour.  It is not just the prospect of more Tory MPs which excites the Tory strategists: it is the prospect of a Labour party returning to its bad old ways of extremism, division and internecine strife.